here's a question - those graphs and charts - does that factor in the enclosures and environments in any way?

like the frequency graph, pretty much the same from the 60i clear up to the ps1000 - with a few minor dips and dives, but does that take into consideration the plastic vs the aluminum vs the mahogany...?

i'm sure how you house the driver should have a direct effect on sound reproduction/quality

I did a comparison between the 225i and 325is when I was demoing different pairs. I can't comment on the 125i because I didn't listen to those. But basically, between the 225i and 325is I noticed was that the 325is were a lot brighter sounding, the bass was a bit more punchy and it sounded a bit airier. So I would imagine being able to hear a difference between the 325is and the 125i.